The above-described paving machines are well known in the prior art. They are used, for example, to install synthetic athletic coating layers on playgrounds, small sports fields, athletic tracks or school athletic facilities and the like. The procedure is such that a plurality of ground covering strips are installed next to each other, one after another, and of course it is desirable that the individual strips be joined seamlessly to each other. Besides a seamless joint, a flush (i.e., no offset) junction of the individual strips is naturally also important. Since it is basically impossible to ensure that the substratum is exactly prepared in the appropriate manner, these paving machines must have corresponding accessory equipment.
The known paving machines are outfitted with smoothing boards, which generally oscillate perpendicular to the direction of travel of the paving machine and thus compact the ground covering material on the substratum, and also smooth it out. At least the oscillatory motion of the smoothing board overlaps the width of the running gear to ensure a seamless joining of the individual strips of ground paving material.
The known paving machines serve to install synthetic coverings, elastic base courses or ground pavements and the like. These ground covers generally consist of ground covering material that is loosely flowing at least during its processing. By ground covering material is therefore meant in the sense of this application that friable and also granular material which then forms the base course in the installed state. The most diverse chemical or physical mechanisms are known for the binding of the granular material; for example, this can be done by mixing in a binder or an adhesive, or also by thermal activation and the like. The term ground covering material is not confined to a special configuration of the material, it can consist of synthetic or mineral raw materials, etc. The invention is not restricted by this.
In order to achieve a flush joining of the individual ground strips with each other, it is known in the prior art how to use a probing unit that interacts in suitable manner with the height adjustment device responsible for the vertical position of the smoothing board. The height adjustment device also has the basic task of determining the layer thickness of the ground covering material being installed. If an inaccuracy results in the substratum, this is corrected in the base course and possibly by raising or lowering the smoothing board, which then changes accordingly the resulting layer thickness of the ground covering material.
It is also the same to the invention if a defined, uniform height offset needs to be achieved (for example, one of a few millimeters or centimeters), which is possible by a corresponding displacement of the offset in the layout of the invented proposal. The flush joining can also be applied to this instance as well.
In the prior art there are known probing units that work without contact to determine the distance of the ground level next to the paving machine from the stationary probing foot and to act accordingly on the height adjustment device. Of course, this involves the ground level of the covering strip already laid down in the previous work step or a corresponding border level (such as a curb stone, etc.). In any case, these methods are not sufficiently accurate.